Introduce shadow mapping using a dedicated depth framebuffer and shader. The block fragment shader now performs percentage-closer filtering (PCF) with Poisson disk sampling and random rotation for soft shadows. The vertex shader outputs light-space coordinates. A new depth shader pair handles rendering from the light's perspective, discarding transparent fragments. The renderer sets up the light projection based on the camera position and sun direction, and applies the shadow factor to diffuse lighting. Day/night cycle can now be toggled off in the world server thread.
* feat(gameplay): add Ocean biome with water generation and heightmap adjustments
- Introduce Ocean biome enum, builder, and detection logic.
- Add ocean water building to all existing biomes and modify heightmap thresholds for low mountainous areas.
- Skip cave and river generation in Ocean (and River) biomes; avoid carving water blocks.
- Comment out border blending call and update block fill logic.
* fix(gameplay): re-enable border blending and protect water in cave gen
* refactor(generation): move ocean water build to later phase
* feat(block): add is_transitional property and refine border blending
* fix(block): set stone block as transitional
* fix(world): generate temporary chunks for surface blend neighbor data
* fix(gameplay): simplify block fill logic in blend_surface_blocks_borders
* refactor(tree): remove debug logging and unused include
* refactor: update water texture
* feat(gameplay): implement transparent block rendering with depth sorting
* fix(world): use camera pos for distance calculations, make water passable
* refactor(player): use ivec3 for block pass check
* feat(camera): add underwater detection
* feat(renderer): add underwater effect with framebuffer post-processing
* feat(block): add gas property and refactor solid block check
* fix(assets): set leaf block transparency to false
* fix(block): set leaf as transparent
* feat: add grass texture and update grass_block texture
* feat: add block data
* feat: add blocks_tool
* feat: add sync info and change function in blocks_tools
* feat: add check and new function
* refactor: make block texture loading data-driven
* feat: add rendering for grass
* feat: passable grass
* feat: random grass place
* fix: memory leak in TextureManager::load_cross_plane_texture
